Fluid-mixing device.



W. M. FULTON.

FLUID MIXING DEVICE. APPLICATION FILED OCT.27. 1913.

2 SHEETSSHEET l- Patented Dec. 12, 1916.

I mwmm W. M..FULTON.

FLUID MIXING DEVICE. APPLICATION FILED 0012?. 1-913.

IT,%@ I3@I Patented Dec.12,19l6.

2 SHEETS-SHEET 2- fzs. AZ. fizz? wbbneoow 1242 www WESTON IVI. FULTON, OF KNOXVILLE, TENNESSEE, ASSIGNOR TO THE FULTON COMPANY,

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OF KNOXVILLE, TENNESSEE, A CORPORATION OF MAINE.

FLUID-MIXING DEVICE.

Specification of Letters Patent. Patentgd E 12 119115 Application filed October 27, 1913. Serial No. 797,667.

To all whom it may concern.-

Be it known that T, WESTON M. FULTON, a citizen of the United States of America, and resident of Knoxville, Tennessee, have invented a new and useful Improvement in Fluid-Mixing Devices, which improvement is fully' set forth in the following specification.

This invention relates to devices for mix: ing fluids of different temperatures to produce a mixture of predetermined temperature, and particularly to automatically controlled devices of this class. As heretofore constructed, these mixing devices are not sufficiently sensitive to maintain the temperature of the mixed fluids with the desired degree of accuracy, and no satisfactory means are provided for indicating accurately the temperature at which the mixture would be maintained by the device nor for readily and quickly adjusting for different temperatures desired in the mixture of fluids discharged.

One of the objects of this invention is to provide a device which controls the temperature of the mixed fluids within very narrow limits and accurately indicates the temperature of the mixture discharged.

A. further object is to provide means for adjusting the device to discharge the mix- .ture at a predetermined temperature and means for thoroughlv mixing the fluids be-' fore discharge.

it. further object is to insure a complete circulation of the fluids around the thermosensitive element before discharge.

These and other objects will be fully ex plained in the detailed description. I

Temperature controlled fluid mixers'find a wide range of application, depending upon the kind of fluids to be mixed and the conditions under which they are to be used. In the following description of my invention I shall describe its use for controlling the. temperature of water delivered to bathtubs and shower-baths where there is a supply of hot and cold water, first, where the mixture is discharged under pressure to the place of use, and second Where it is discharged without pressure. Tt is to be dis tinctly understood, however, that I do not confine the use of my invention to any particular fluid, as it is generally applicable where fluids at different temperatures are .to be mixed to obtain a mixture at a predetermined temperature and to automatically maintain the delivery of the mixture at such temperature.

In order that the invention may be readily understood reference is had to the accompanying drawings which illustrate two mechanical embodiments of the inventive idea and are intended to assist the description of the invention and not to define the limits thereof.

Tn the'drawingsz-Figure 1 is a view in longitudinal central vertical section showing the interior construction of a fluid mixer embodying. my improvements; Fig. 2 is a, transverse sectional view looking downward, taken on line 22 of Fig. 1; Figs. 3 and l are similar views taken on the lines 3-3 and 4% of Fig. 1; Fig. 5 is a sectional detail in perspective; Fig. 6 is a vertical, central sectional view showing a modified form of my improved mixer; Fig. 7 is a perspective new of the upper portion of the casing showing the index and temperature scale; and Fig. 8 is a sectional view taken on the broken line 8-8 of Fig. 6.

Referring to Fig. l, the device is provided with a cast metal casing 1 externally threaded at its upper end to receive a housing member 2 adapted to be closed by a screw-plug 3. The lower end of the casing 1 is closed by a screw-cap 4-, preferably provided with an internally threaded discharge connection 5. The casing 1 is provided with a hot water inlet connection 6 and a similar cold water inlet connection 7. Within the central portion of the casing 1 is fitted a two-part valve bushing or casing 8 supported by and held away from the walls of the casing 1 by projections 9 arranged in different planes and permitting intercommunication between the annular space between the bushing 8 and walls 1, and the lower part of the casing. This valve bushing is shown in sectional detail in Fig. 5 and is made .up of two semi-cylindrical sections slightly tapered to fit a corresponding taper given to the lugs 9. The bushing 8 is provided with screw-threaded reduced ends 10 at its opposite ends for receiving clamping rings 11. On the interior surface of the two halves of the bushing is formed a plurality of ledges 12 which are provided as shown with valve seats. In each half of the bush ing 8 is an opening 13 appearing in Fig. 1. When the bushing is in position in its casing, each opening 13 registers with its cor responding inlets 6 and 7 and permits fluid to enter the upper and lower spaces or chambers formed by ledges 12. The bushing 8 is also provided with a plurality of discharge openings 14 located centrally in its walls, permitting free communication between the annular space referred to and the central space within the bushing. A plurality of balanced valves 15 integral with or mounted on a hollow valve stem 16 is adapted to cooperate with valve seats 12 to control the relative quantities of fluid to be mixed in passing through the device. This hollow valve stem 16 receives a rod 17 which has its opposite ends screw-threaded for receiving lock-nuts 18 between which the valve stem is held on the rod. For the purpose of guiding the valves to their seats, the upper and lower valves are provided with the usual guide wings, not lettered. A certain amount of play is allowed between the rod 17 and bushing 8 for final assemblage of parts. The lower part of the casing 1 is somewhat enlarged for receiving a vibratory thermosensitive vessel 19 which contains a volatile liquid, the vapor of which under variations of temperature of the mixed fluid in contact with the vessel causes it to expand and contract. The end walls. of this vessel are closed by inelastic plates 20, each provided with an internally projecting screw-threaded hub 21. The lengths of these hubs are such as to prevent too near approach of the end walls and thus protect the sharp bending of the corrugations in the'walls of the vessel. The lower end wall 20 rests on a' raised portion or seat formed in supporting plate 22.and is made fast thereto by means of a screw which passes through the plate and enters the threaded hub 21. The upper hub 21 receives the lower threaded end of rod 17 carrying the valve stem 16. The upper end of the casing 1 is closed by a reentering vibratory wall 23 of the same diameter as vessel 19 and having its upper edge fast to an annular plate 24, the rim of which'is flat and is clamped down on the top edge of the casing wall 1 by the under surface of cap 2. The vibratory wall has an inelastic end closure 25 provided with a hub like those on the end walls of vessel 21. The upper screwthreaded end of rod 17 engages the threaded socket in this hub to constitute the upper support for the valve carrying the rod 17. External spring pressure is applied to the thermosensitive vessel through rod 17 by means of a spring 26, the lower end of which rests on the end wall 25 of vessel 23 and is kept in place by its hub. The upper end of spring 26 receives a compressing nut 27 provided with a pointer 28 extending through a slot in the wall of cap 2, on one edge of which is marked a temperature scale. Threading nut 27 is a left-hand screwthreaded rod 29 having, a smooth round upper portion passing through an opening in plug 3. Rod 29 is held in plug 3 against longitudinal movement by means of a shoulder 30 and a nut 31, under which latter is held the hub of a hand wheel 32 for rotating the rod 29. A stop nut 33 is secured to the end of rod 29 by a cotter pin or by solder, or both, for the purpose of preventing nut 27 riding off the end of rod 29.

In order that the thoroughly mixed fluids may circulate about and come in complete contact with every portion of the thermosensitive element, special means are provided.

v Within the lower part of the asing 1 and surrounding the thermosensitive element or vessel 21 is located an inverted cup-shaped vessel 34 provided with a central opening 35 in its inverted end wall for admitting the lower threaded end of the valve operating rod 17. The vessel is seated in a recess formed in anannular ledge 36 projecting from the body of the casing 1 and is held in this seated position by aid of base plate 22 which is screw-threaded and is secured in an annular ledge 37 projecting from the wall of the casing 1. The plate 22 is screwed against the end of vessel 34 and holds it against its seat in ledge 36. In the left-hand half of upper ledge 36 (see Fig. 3) are two openings 38, which permit free communication between the annular space around the valve bushing 8 and the space below and confined to one side of the cup 34. The annular space around cup 34 is divided into two spaces by shallow partitions 39 formed in the wall of easing 1. The space on the left of partitions 39 receives the mixed fluids flowing downward and directs them to an opening 40 at the bottom of the cup 34. The space on the right of partitions 39 receives fluids escaping from cup 34 through opening 41 and guides them to the discharge outlet 5. For the purpose of draining the device, a drain-opening 42 is made in plate 22.

The operation of the device thus far described is as follows: Assuming the parts assembled and that the temperature desired to be maintained in the outgoing mixture is 90 F., and that inlet 6 is connected with a source of water above this temperature, and that inlet 7 is connected with a source below this temperature, hand wheel 32 is given a right-hand rotation causing nut 27 to pass downward, compressing spring 26 until index 28 registers with the 90 mark of the temperature scale. This compression of spring 26 overcomes the tension of the vapor in vessel 22 and collapses it, carrying with it rod 17 and valve stem 16 thereby seating the lower set of balanced valves 15 and closing the cold water supply. At the same time the balanced valves 15 of the upper set are moved away from their seats, there- Laeeaieo by opening their ports to the hot water supply inlet 6. This water passes through the hot water valve ports filling the space about the vessel 23 and the central space in the valve bushing, and flows downward through the annular space between the casing wall 1 thermostat 19, the heat expands the vapor therein overcoming the pressure of spring 26 which was set to correspond to a temperature below that of the hot water and thus moves the stem 17 to throttle down the admission of hot water and to open the supply of cold water which mingles within and on the outside of valve bushing 8 with the incoming hot water to reduce its temperature. lWhen the amount of cold water thus admitted and mixed with the hot water brings the temperature of the mixture to 90, the expansive force of the vapor inside the thermostat vessel 19 will just be suflicient to hold the valves in such position as to admit the proper amounts of hot and cold water to maintain the mixture at 90. Should for any reason too much hot water or too much cold water enter the device, the resultant change of temperature in the outgoing mixture aflects the thermostat which readjusts the valves to bring back the temperature of the mixture to 90. fluctuations in temperature cause a marked degree in expansion of the controlling ves-.

sel, thus enabling the temperature of the mixture to be controlled between very narrow limits. ()wing to the manner of assem-' bling the valves and valve bushing, the valves can be balanced in pairs on a single stem, and the fact that the diameters of the vessels 19 and 23 are made equal the pressure of the fluid passing through the mixer can neither have a tendency to open or close the valves or affect in any way the expansion and contraction of the thermostatic vessel 19.

In Figs. 6 to 8, I have illustrated another constructional form of my invention diflering from the mixer above described, which is designed to deliver mixed fluids under pressure, whereas in this form of the device the mixed fluids are delivered free from pressure. Where the mixed fluids are delivered under pressure, Infiilllr are employed in the above-described device for preventing the fluid pressure in the casing affecting the Slight thermostatic element. W here such fluid pressure in the device does not exist or exist to any appreciable extent, such precautionary means may be omitted. In the present form of the invention, the hot and cold fluid inlets 6 and 7 are located in the same level and opposite each other for convenience of connection with the pipe connections of a bathtub, as these connections are usually arranged parallel, and this provision permits dispensing with bends or elbow fittings. The valve bushing 8 is of the same two-part construction and is supported away from the walls of the casing 1 by projections 9 in the manner previously described, except that the upper opening 43 in the bushing 8 receives an enlarged part 44 of the valve rod 45 which closes the opening and cuts oil access of fluid entering the casing from the cap space above the bushing. The valve stem 45 is provided with valves which are balanced in the manner previously described. The housing 2 for the temperature adjusting means is closed by an internally threaded cap 46 and is made smaller than in the first-described construction by reason of the omission of the vibratory vessel. tii'pring 26 presses directly on the upper enlarged end 44 of the valve rod and the latter rests in a recessed stem of a cup-shaped member 47 seated in a depression in the upper end wall 48 of the thermosensitive vessel 19'. This construction of the member 47 reduces metallic contact between the wall of the vessel and other working parts and the fluids pass after mixing in the spaces above the thermostatic element, so that they will be greater than the combined areas of the inlets 6 and 7. The outlet port 51 is also made with an area greater than the combined areas of inlets 6 and 7. By this means the expansion and contraction of the thermostatic member 19 is freed from the influence of fluid pressure.

In operation, assuming the valves are in the position shown in Fig. 6, hot water enters inlet 6, flows up through channel 52 into a space in the upper part of valve bushing 8, then through the upper open port past the upper side of valve 15, thence through openings 14 in the walls of the bushing and into the annular space between the casing wall and that of the bushing and downward to the passages 38, only one of which appears in the figure. The mixed liquids then follow the course previouslydescribed around the thermostatic element and are discharged from the device. The thermostatic element responds to any change of temperature in the mixture above or below that for which it is set by the regulating means and throttles either the hot or cold water supplies to the proper degree to give a mixture of the required temperature in the same manner as in the construction first desaid valve and subject to pressure of said fluids for rendering the operation of said valve independent of variations of fluid pressure.

2. In a device for mixing fluids of different temperatures -to produce a mixture of a predetermined temperature, a conduit hav-- ing inlets for admitting fluids at different temperatures and a discharge outlet, valves controlling the relative flow of fluids through said inlets, thermosensitive means for operating said valves, means for setting the thermosensitive means to operate above and below a predetermined temperature to automatically maintain the outgoing mixture at said predetermined temperature and other means associated with said valve and subject to pressure of said fluids for rendering the operation of said valve independent of variations of fluid pressure.

3. In a device for mixing fluids of different temperatures to produce a mixture of a predetermined temperature, a conduit having inlets for admitting fluids at different temperatures and a discharge outlet, valves for controlling the relative flow of fluids through. said inlets, thermosensitive means for operating said valves, means associated with said valves and subject to pressure of said fluids for rendering the operation of said valves independent of variations in fluid pressure, and means for setting the thermosensitive means to operate above and below a predetermined temperature to automatically maintain the outgoing mixture at said predetermined temperature.

4. In a device 'for mixing fluids of difl'er ent temperatures to producea mixture of a predetermined temperature, a conduit having inlets for admitting fluids at diiferent temperatures and a discharge outlet, valves. .for controlling the relative flow of fluids through said inlets, thermoscnsitive means for operating said valves, means associated with said valves and subject to pressure of said fluids for rendering the operation of said valves independent of variations in fluid pressure, and temperature indicating means for setting the thermosensitive means to operate above and below a predetermined temperature to automatically maintain the outgoing mixture at said predetermined temperature.

5. In a device for mixing fluids of different temperatures to produce a mixture of a predetermined temperature, a conduit having a plurality of fluid inlets admitting fluids at different temperatures and a fluid outlet, valves for controlling the relative flow of fluid through said inlets, a thermosensitive vessel exposed to the outgoing mixed fluids for operating said valves to control said fluid supply inlets and maintain the temperature of the mixture discharged substantially constant and means associated with said valves and subject to pressure of said fluids for rendering the operation of said valves independent of variations in fluid pressure.

6. In a device for mixing fluids of different temperatures to produce a mixture of a predetermined temperature, a conduit having a plurality of fluid inlets admitting fluids at different temperatures and a fluid outlet, valves for controlling the flow of fluid through said inlets, a thermosensitive vessel exposed to the outgoingmixed fluids foroperating said valves to control said fluid supply inlets, means for adjusting the thermosensitivc vessel to maintain a predetermined temperature in the mixture discharged and means associated with said valves and subject to pressure of said fluids for rendering the operation of said valves independent of variations in fluid pressure.

7 In a fluid mixing device, a casing havfluids at different temperatures and a fluid outlet for the mixed fluids, balanced valves in said casing controlling flow of fluids through said inlets, a thermosensitive Vessel in the casing exposed to the outgoing mixed fluids for operating said valves, and adjustable means adapted to indicate temperature and to act on said vessel to adjust the latter to maintain a predetermined temperature in the outgoing mixture as indicated by said means and means associated with said valves and subject to pressure of said fluids for rendering the operation of said valves independent of variations in fluid pressure.

8. In a fluid mixing device, a casing having a plurality of fluid inlets admitting fluids at difl'erenttemperatures and a fluid ing a plurality of fluid inlets admitting naoa so outlet for the mixed fluids, balanced valves in said casing controlling flow 01. fluids through said inlets, a thermosensitivc vessel in the casing exposed to the outgoing mixed fluids for operating said valves, a flexible wall exposed on one side to fluid pressure in said casing and having connection with said vessel for rendering the operation of said valves independent of variations of said fluid pressure, and an adjustable spring pressed member having temperature indicating means associated therewith and adapted to apply pressure to said vessel and regulate the temperature of the outgoing mixture as indicated by said indicating means.

9. in a fluid mixer, a casing having inlets for admitting fluids at different temperatures and an outlet for discharge of the mixed fluids. balanced valves for controlling flow of fluid through said inlets, a thermosensitive vessel exposed to the outgoing mixed fluids for operating said valves, adjustable spring pressed means for applying pressure to said vessel through said valves to cause said vessel to respond to a predetermined temperature of the outgoing mixture and control the fluid supplies to maintain this temperature of the mixture constant, a flexible wall exposed on one side to fluid pressure in said casing and having connection with said vessel for rendering the operation of said valves independent of variations of said fluid pressure.

10. in a fluid mixing. device, a casing having inlets for admitting fluids at different temperatures and an outlet for the mixed fluids, balanced valves for controlling said inlets, a vibratory thermosensitive vessel exposed to the outgoing mixed fluids for operating said valves to maintain a constant temperature in said mixture, and means for counteracting effects of fluid pressure on the outer walls of said vessel.

11. in a fluid mixer, a casing having inlets for admitting fluids at different temperatures and an outlet for the mixed fluids, balanced valves for controlling said inlets, a vibratory thermosensitive vessel exposed to the outgoing mixed fluids for operating said valves to maintain a constant temperature in said mixture, means for counteracting efl'ects of fluid pressure on the outer walls of said vessel, and adjustable spring pressure means acting on said vessel through said valves to ,maintain a predetermined temperature in said mixed fluids.

12. in a device for mixing fluids, a casing having fluid inlets and a fluid outlet, a thermosensitive vibratory vessel in one end of said casing and in the opposite end a closure consisting of a vibratory wall exposing a surface to fluid pressure equal to that of the first-named vessel, an inflexible rod connecting the movable ends of said vessels and supporting a plurality of valves, a two-part valve bushing having openings into said casing space controlled by said valves and other openings to said inlets, and a means associated with said vessel for directing the circulation of the mixed fluids around the vessel.

13 In a device for mixing fluids of different temperatures to produce a mixture of a predetermined temperature, a conduit having inlet-s for admitting fluids of different temperatures and a discharge outlet, a valve casing adapted-to be inserted in said conduit and form with the wall of the conduit an annular mixing space for the fluids, said casing having valve controlled ports communieating with said inlets and discharge openings for conducting said fluids into the said annular space, thermosensitive means exposed to the outgoing mixed fluids for oper ating said valves to automatically control the relative quantities of fluids for maintaining the outgoing mixture at constant temperature, the total cross section of said inlets being less than that of any succeeding passage or passages through which the mixed fluids pass for the purpose of preventing accumulation of pressure in the device.

14. In a temperature controlling device, the combination of a casing having inlet and outlet ports, a valve controlling one of said ports, thermostatic means for actuating said valve, a diaphragm connected to said thermostat, and a spring associated with said diaphragm and acting to restrict the expanoo sion ofsaid thermostat, an increased pressure within said casing acting on said diaphragm to compress said spring and reduce the resistance to be overcome by said thermostat, substantially as described.

15. In a device of the class described, the combination of a casing having a plurality of inlets and an outlet, a valve controlling said inlets, a thermostat including a self-expansible element disposed within said casing and adapted to be eflected by pressure within said casing, spring means and a diaphragm associated with said thermostat said diaphragm being adapted to act upon said spring means and relatively reduce the re- 11a sistance to expansion of said thermostat in proportion to the increase in pressure within said casing, substantially as described.

16. in a device for mixing fluids of difl'erent temperatures to produce a mixture of a predetermined temperature, a conduit having a. plurality of fluid inlets admitting fluids at diflerent temperatures and a fluid outlet, valves for controlling the relative flow of fluid through said inlets, an expansible and collapsible vessel charged with a volatile fluid and exposed to the outgoing mixed fluids for operating said valves to' control said fluid supply inlets and maintain the temperature of the mixture dis- 13o expansible and collapsible corrugated resilient vessel having a movable end wall operatively connected to said valve means and charged with a volatile fluid which is in heat interchanging relation with the aforesaid mixture, and resilient corrugated means mounting said valve means and balancing the same.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

WESTON M. FULTON. WVitnesses I. A. MARTIN, F. C. REEDER. 

